Biomolecules Review

Long term energy, insulation for the body, and cushioning for vital organs, are all functions of which organic molecule?

• carbohydrate

• fat

• protein

• sugar

A scientist discovers a species of bacteria. The relative percentage of adenine base in its DNA is about 23%.

What is the expected percentage for the other three bases?

• thymine: 27%; guanine: 27%; cytosine: 23%

• thymine: 23%; guanine: 23%; cytosine: 23%

• thymine: 23%; guanine: 27%; cytosine: 27%

• thymine: 27%; guanine: 23%; cytosine: 23%

Carb-loading is a strategy that marathon runners have been known to do several days before a big race. This involves eating foods high in carbohydrates.

How does this benefit the athlete?

• It increases the number of amino acids available to build muscle mass.

• It increases the starches stored in the athlete's muscles.

• It increases the storage of glycogen for energy in the muscles.

• It increases body fat which warms and protects the muscles.

What is the fundamental element found in all organic compounds studied by chemists?

• carbon

• hydrogen

• oxygen

• nitrogen

Tags

NGSS.HS-LS1-6

Which chemical formula represents a carbohydrate and why?

• CO₂ because the ratio of O to C is 2:1.

• C₁₂H₂₂O₁₁ because the ratio of H to O is 2:1.

• C₂H₇NO₃S because the ratio of O to C is greater than 2:1.

• CH₃CH₂CH₂COOH because the ratio of H to O is greater than 2:1.

A student is reading about the chemical composition of a category of molecules. The molecules are found as repeating units of proteins.

What type of molecule are the repeating units?

• amino acids

• fatty acids

• monosaccharides

• nucleotides

Tags

NGSS.HS-LS1-6

Which factor best explains why lipids are important components of waterproof coatings of organisms?

• Lipid molecules are polar and generally soluble in water.

• Lipid molecules are polar and generally not soluble in water.

• Lipid molecules are non-polar and generally not soluble in water.

• Lipid molecules are non-polar and generally soluble in water.

In which form do proteins help transport oxygen and carbon dioxide in the human body?

• enzymes

• hemoglobin

• hormones

• keratin

Examine the section of nucleic acid. Which explanation best describes the molecule shown?

• Structures X, Y, and Z represent a nucleotide of a double-stranded DNA molecule.

• Structures X, Y, and Z represent a phosphate group of a double-stranded DNA molecule.

• Structures X, Y, and Z represent an amino acid on an RNA molecule with a 5-carbon ribose sugar.

• Structures X, Y, and Z represent a gene on an RNA molecule with a 5-carbon ribose sugar.

Tags

NGSS.HS-LS1-1

A student created a table that lists several features of an RNA molecule. The student made an error while creating the table. Which statement describes the change that the student needs to make in the table?

• The type of base should be thymine instead of uracil.

• The type of sugar should be ribose instead of deoxyribose.

• The structure should be a double helix instead of a single strand.

• The function should be to help in the synthesis of DNA instead of protein.